Display panels of the liquid crystal display apparatuses and the like are usually made of glass substrates which are brittle material substrates. The liquid crystal display apparatuses includes display panels formed by bonding a pair of glass substrates with an appropriate space therebetween and enclosing liquid crystal into the space.
For manufacturing such display panels, a process to cut out a plurality of display panels of a bonded mother substrate by cutting the bonded mother substrate which is obtained by bonding mother glass substrates is performed. A scribing apparatus used for cutting bonded mother substrates is disclosed in Publication for Utility Model Opposition No. 59-22101.
FIG. 93 to a schematic view showing a structure of the scribing apparatus. A scribing apparatus 950 includes tables 951 for respectively putting a side edge portion of a bonded mother substrate 908 thereon. On the tables 951, clamp members 952 for clamping the side edge portions of the bonded mother substrate 908 are attached. The scribing apparatus 950 includes a pair of cutter heads 953 and 954 respectively provided above and below the bonded mother substrate 908. The cutter heads 953 and 954 oppose each other with the bonded mother substrate 908 interposed therebetween.
In the scribing apparatus 950 having such a structure, when the bonded mother substrate 908 is fixed to the tables 951 with the clamp members 952, a front surface and a back surface of the bonded mother substrate 908 are scribed at the same time by the pair of cutter heads 953 and 954 to form scribe lines.
However, in such a scribing apparatus 950, a breaking apparatus for cutting the bonded mother substrate 908 on which the scribe lines are formed is separately required. Further, for cutting the bonded mother substrate 908 by a breaking apparatus, it is necessary to reverse the bonded mother substrate 908 (to turn the substrate upside down) after cutting one of the mother substrates of the bonded mother substrate 908 for cutting another substrate. For cutting display panels out of the bonded mother substrate 908, a complicated line system has to be established.
For cutting display panels out of the bonded mother substrate 908 by using such a scribing apparatus 950, a complicated line system having a footprint few times larger then that of the scribing apparatus 950 has to be established. This is one of the reasons increasing the manufacturing cost of display panels.
Further, in the scribing apparatus 950 shown in FIG. 93, the bonded mother substrate 908 is scribed from both front surface and back surface at the same time. However, the process direction is limited to one direction, and cross scribing (scribing along directions such that the scribe lines are orthogonal to each other) is impossible.
This means that another scribing apparatus is necessary for cross-scribing. There is a problem that the scribing process efficiency for the bonded mother substrate 908 to significantly low.
Moreover, there is a problem that the process cannot be performed along two directions which are orthogonal to each other in one setting when the mother substrate is cut from both the front surface and the back surface by using an apparatus similar to the above-described scribing apparatus 950.
The present invention is to solve such problems and the object thereof is to provide a substrate cutting system and a substrate cutting system which has a small foot print and a compact structure, and which can efficiently cut various types of mother substrates.